FIELD OF THE INVENTION
This invention was made with government support under National Cancer Institute Grant No. CA-54039 awarded by the National Institutes of Health. The United States government has certain rights in the invention.
The present invention relates to a process for preparing safer forms of grilled or flame-broiled foods by reducing the presence and formation of known and suspected carcinogenic compounds in such foods without sacrificing the flavors and organoleptic properties normally associated with such foods. The invention also relates to a grill apparatus for carrying out such a process.
The process and grill apparatus utilize a medium which is capable of separating or fractionating the desired lower boiling point flavor compounds from the undesired higher boiling point carcinogenic compounds due to the temperature differential of the medium. This medium, called a fractionating medium, allows the desired lower boiling point flavor compounds of the smoke produced during grilling to pass through the medium and contact the food, thereby giving it the characteristic grilled or smoked flavor. The higher boiling point carcinogenic compounds contained in the smoke, however, are retained on the fractionating medium, thereby preventing them from contacting the food. The resulting grilled food has the characteristic flavor and organoleptic properties of foods prepared by conventional grilling techniques, but contains reduced amounts of known or potential carcinogenic compounds.
Because of the satisfactory flavor, texture, appearance and other organoleptic properties associated with grilled and flame-broiled foods, they continue to be increasingly popular. Grilled foods have for many years found favor with individuals using small home-style grills and with commercial establishments such as restaurants.
Unfortunately, it is well known that grilled, flame-broiled and barbecued foods contain higher amounts of potential and known carcinogenic compounds than the same foods prepared by alternative cooking methods. For example, conventional grilling results in direct charring of foods and is a major cause of carcinogen formation in grilled foods. Since such foods are increasingly popular both at home and in restaurants, they may present an elevated health risk.
The formation of known and potential carcinogens is known to occur as a result of the cooking of foods. The quantity of these carcinogenic compounds in prepared foods can be traced to the type of cooking preparation method. For example, Lijinsk, W. and Shubik, P., 1964, Benzo(a)pyrene and Other Polynuclear Hydrocarbons in Charcoal-broiled Meat, Science, 145:53, reported the presence of benzo[a]pyrene (BaP) and related polynuclear aromatic hydrocarbons (PAH) in charcoal-broiled beef. They found that the crust of beef contained 8 to 50 micrograms of BaP/kg. Lintas et al., 1979, Determination of Benzo(a)pyrene in Smoked, Cooked and Roasted Food Products. Food Cosmet. Toxicol., 17:325, on the other hand, found a much lower amount of BaP (0.05 micrograms of BaP/kg) in hamburger heated in a pan on an electric grill.
It is also known that the smoke produced during a conventional grilling process contains a variety of polynuclear aromatic hydrocarbons. For example, Lijinsk, W. and Shubik, P., 1964, Benzo(a)pyrene and Other Polynuclear Hydrocarbons in Charcoal-Broiled Meat, Science 145:53, found that a crust of beef, which consisted of the deposited smoke condensate, contained 8 to 50 micrograms of BaP/kg. Nagao et al., 1977, Mutagens in Foods and Especially Pyrolysis Products of Protein, In Progress in Genetic Toxicology, p. 259, Scott, D. Dridges, B. A., and Sobels, F. H. (Eds), Elsevier/North-Holland, Amsterdam, reported that the charred surface of beef (190 g) contained 860 micrograms of polynuclear aromatic hydrocarbons, with the smoke condensates having a much lower level of polynuclear aromatic hydrocarbons than the tars from the pyrolyzed amino acids.
According to some estimates approximately 40% of cancer incidence is due to food. Wynder, 1983, Reflections on Diet, Nutrition and Cancer, Cancer Research, 43:3024. More recent studies have also come to a similar conclusion. Vuolo, L. L. & Schuessler, G. J., 1985, Putative Mutagens and Carcinogens in Foods. VI. Protein Pyrolyzate Products. Environ, Mutagen, 7:577-98. Consequently, there is an urgent need for better grilling technology and a safer means of preparing grilled and flame-broiled foods. The numerous prior art attempts to avoid the formation of known and potential carcinogens in cooked foods show the critical need for such technology.
The following recommendations have previously been proposed for reducing the formation of carcinogens in food products during cooking. Lijinsky, W. and Ross, A. E., 1967, Food Cosmet. Toxicol., 5:343, found that the level of polynuclear aromatic hydrocarbons was influenced by the level of fat in meat and that reducing the amount of fat reduced the formation of polynuclear aromatic hydrocarbon products. Avoiding direct contact of the food with the flames and thereby preventing charring of the foods has also been recommended. Separating the foods from the heating source, such as cooking in a pan or a skillet, while preventing the direct charring of the meat, causes great changes in the flavor and character of the meat when compared to foods prepared by conventional grilling techniques. It has also been suggested to discard the fat from the food during cooking and to add artificial smoked flavor to the food product. None of the above-mentioned solutions is ideal since none of them renders a product having the character and properties of a conventionally grilled or flame-broiled food. Moreover, it is unlikely that the consuming public will use a grill that produces a food product having a radically altered flavor and appearance.
The present invention accomplishes the same objective of the prior art by lowering the amount of known and potential carcinogens in prepared foods, but does so in a completely different manner, and quite unexpectedly does so without sacrificing the desired flavor and organoleptic properties associated with grilled or flame-broiled foods.